WATFORD CITY – The cause of an emulsion spill on a well pad in McKenzie County is under investigation.

Emulsion is a mix of crude oil, produced water and natural gas as it comes out of the well.

North Dakota Department of Environmental Quality was notified on Thursday of the spill on the well pad about three miles west of Watford City. The well pad is operated by Newfield Production Company.

The spill occurred in the flowline connecting the wellhead to the treater unit.

Newfield Production Company estimates 413 barrels of emulsion were released on the well pad. An undetermined quantity of emulsion was windblown off the well pad, impacting pastureland.

Personnel from the NDDEQ are inspecting the site and will continue to monitor the investigation and remediation.